N-pyridyl-formimino ethers

ABSTRACT

NEW N-PYRIDYL-FORMIMINO ETHERS OF THE FORMULA   R2,(R1-O-CH=N-)PYRIDINE   WHEREIN R1 REPRESENTS A SATURATED STRAIGHT OR BRANCHED CHAIN ALKYL GROUP OF 7 TO 16 CARBON ATOMS, A CYCLOALKYL GROUP OF 5 TO 6 CARBON ATOMS, A BENZYL OR PHENYLETHYL GROUP OR A DIMETHYLAMINOETHYL OR DIETHYLAMINOETHYL RADICAL AND R2 REPRESENTS HYDROGEN, HALOGEN, NITRO OR LOWER ALKYL. THE NEW COMPOUNDS ARE USEFUL AS ANTHELMINTICS AND CERCARICIDES.

United States Patent 3,590,037 N-PYRIDYL-FORMIMINO ETHERS Pal Benko, 7 Parcsay Vilmos utca; Laszlo Pallos, 8a Ugocsa utca; and Fercnc Ordogh, 25-27 Ozike utca, all of Budapest XII, Hungary; and Julianna Rosdy, nee Kiss, 5 Muk S. utca, Budapest XHI, Hungary No Drawing. Continuation-impart of application Ser. No. 717,013, Mar. 28, 1968. This application Apr. 21, 1970, Ser. No. 30,591

Int. Cl. C07d 31/42 US. Cl. 260240 1 Claim ABSTRACT OF THE DISCLOSURE New N-pyridyl-formimino ethers of the formula wherein R represents a saturated straight or branched chain alkyl group of 7 to 16 carbon atoms, a cycloalkyl group of 5 to 6 carbon atoms, a benzyl or phenylethyl group or a dimethylaminoethyl or diethylaminoethyl radical and R represents hydrogen, halogen, nitro or lower alkyl. The new compounds are useful as anthelmintics and cercaricides.

The present application is a continuation-in-part of our copending application Ser. No. 717,013, filed Mar. 28, 1968, now abandoned.

The invention relates to new N-pyridyl-forrnimino ethers of valuable therapeutic effects, as well as to a process for the preparation of such N-pyridyl-formimino. ethers.

The new compounds of the present invention can be characterized by the formula wherein R represents a saturated straight or branched chain alkyl group of 7 to 16 carbon atoms, a cycloalkyl group of 5 to 6 carbon atoms, a benzyl or phenylethyl group or a dimethylaminoethyl or diethylaminoethyl radical and R represents hydrogen, halogen, nitro or lower alkyl.

The N-pyridyl-formimino ethers of Formula I can be prepared according to the present invention by reacting a formimino-alkyl ether of the formula wherein X represents an alkyl group of 1 to 4 carbon atoms, and R has the same meaning as above, with an alcohol of the formula HOR (III) wherein R has the same meaning as above. This reaction can be performed preferably in the presence of an organic solvent, and of an alkali metal or an alkali alkoxide. The alcohol of Formula III may be used in an equimolecular amount or, more preferably, in excess; the reaction proceeds in general readily at the reflux temperature of the reaction mixture. The obtained N-pyridyl-formimino ethers of Formula I may be converted in known manner, if desired, into quaternary ammonium derivatives.

The new compounds of the present invention show a potent and selective anthelmintic action against well developed worms of the species Tubifex rivularium. The anthelmintic elfects of the new compounds are stronger than those of the anthelmintic agents known and used hitherto. The new compounds also show a cercaricidal activity, which is unusual for anthelmintics.

The invention is illustrated in more detail by the following examples.

EXAMPLE 1 The mixture of 12.5 g. (0.0832 mol.) of N-(4-pyridyl)- formimino-ethyl ether and 21.6 g. (0.2 mol.) benzyl alcohol was heated in the presence of 0.05 g. of metallic sodium for two hours at -120 C. The ethanol formed during the reaction was distilled off continuously; the end of the reaction was shown by collecting of the theoretical amount of ethanol in the distillate. The distillation residue was then fractionated; the obtained N-(4-pyridyl)-formimino-benzyl ether boils under 0.1 mm. Hg at 70-78 C.

EXAMPLE 2 25 g. (0.1664 mol.) of N-(4-pyridyl)-formimino-ethyl ether was mixed with 24.42 g. (0.2 mol.) of B-phenyl-ethyl alcohol, 0.05 g. of metallic sodium was added to the mixture and it was heated for 3 hours at -140 C. The reaction product was then subjected to fractionated distillation; the obtained N-(4-pyridyl)-formimino-(fir-phenylethyl) ether boils under 0.05 mm. Hg at 138-140 C. The following additional compounds have also been prepared by the method of the above example:

N- Z-pyridyl) -formimino-octyletherB .P. 15 0- N- 3 pyr i dyl -formimino-octylether-B.P. 162- N- g pyr idyl)-formimino-octylether-B.P.

N- Zmeihyl-Z-pyridyl) -formimino-octylether-- EXAMPLE 3 The mixture of 150.18 g. (1 mol.) of N-(3-pyridyl)- formimino-ethyl ether and 242.4 g. (1 mol.) of cetyl alcohol was dissolved in 500 ml. of benzene. The solution was then heated to the boiling point and the formed ethanol was distilled off as an azeotropic mixture with benzene. At the end of the reaction the benzene was distilled oif too, and the residue was subjected to fractionated distillation. The obtained N-(3-pyridyl)formimino cetyl ether boils under 0.05 mm. Hg at 193195 C. The following additional compounds have also been prepared by the method of the above example:

N- 2-pyridyl -formimino-n-decylether-B.P. 149 C. N-(4-pyridyl)formimino-n-decylether-B.P. :152 C. N-(3-pyridyl) -formimino-dodecylether-B.P. 192 C.

EXAMPLE 4 150.18 g. (1 mol.) of N-(3-pyridyl)-formimino ethyl ether and 300.46 g. (3 mol.) of cyclohexanol were reacted in the presence of 0.1 g. of metallic sodium as described in Example 1. The obtained N-(3-pyridyl)-formimino cyclohexyl ether boils under 0.2 mm. Hg at 123-l24 C. pyridyl)-formimino fi-diethylaminoethyl ether boils under 0.2 mm. Hg at l70-l82 C.

EXAMPLE 5 15 g. (0.1 mol.) of N- (3-pyridyl) -formimino ethyl ether and 47.4 g. (0.3 mol.) of n-decyl alcohol were reacted for half an hour in the presence of 0.05 g. of metallic sodium, as described in Example 1. The obtained N- (3-pyridyl)-formimino n-decyl ether boils under 0.2 mm. Hg at 156-158" C. The following additional compounds have also been prepared by the method of the above example:

N- 2-pyridyl -formimino-cetyletherM.P. 4-5 5 .5 C. N- (4-pyridyl) -formimino cetylether--B.P. 200-203 N-(5-chloro-2-pyridyl) -formimino cetyletherM.P. 59-

EXAMPLE 6 The mixture of 150.18 g. (1 mol.) of N-(2-pyridyl)- formimino ethyl ether and 122.16 g. (1 mol.) of ,8-phenyl ethyl alcohol in 600 ml. of toluene was heated at 110- 140 C. for three hours in the presence of 0.05 g. of metallic sodium. The product was isolated as described in Example 2; the obtained N-(2-pyridyl)-formimino phenyl-ethyl ether boils under 0.05 mm. Hg at 135 C.

EXAMPLE 7 The mixture of 15.0 g. (0.1 mol.) of N-(2-pyridyl)- formimino ethyl ether, 21.6 g. (0.2 mol.) of benzyl alcohol and 0.05 g. of metallic sodium was reacted as described in Example 2. The obtained N-(2-pyridyl)-formimino benzyl ether boils under 0.5 mm. Hg at 148 C.

EXAMPLE 8 16.42 g. (0.1 mol.) of N-(4-methyl-2-pyridyl)-formimino ethyl ether were reacted in the presence of 0.1 g. of

l0rum(T) and Schistosoma mansoni cercaria (C) of the new compounds and, for comparison, those of analogous C alkyl compounds disclosed in the Hungarian patent; the significantly higher activity of the new compounds can be seen from this table.

TABLE I.MINIMAL INHIBITING CONCENTRATIONS IN MG. PERCENT AGAINST ENC'HYTRAEUS ALBIDUS (E), TUBIFEX RIVULOR UM (T) AND SCHISTOSOMA MANSONI OERCARIA (O) E T C N -(4-pyridyl) -fo1mimino-octylether 1. 7-3. 5 15. 5 0. 8 N-(4- )yridyD-formimino-dodecylether- 15. 5 3. 5-7. 5 0. 8-1. 7 N-(4-pyridy1)-formiinino-eyclohexylether 3. 5 1. 7-3. 5 1. 7 N-(4-pyridyl)-form.imino-cyclopentylether 1. 7-3. 5 1. 7 3. 5 N-(3-pyridy1)-formimino-octy1ether 1 7-0. 8 15. 5 0. 4-0. 8 N-(3-pyridyl)-f0rniinino-dodecylether 1. 7 0. 8 0. 4-0. 1 N-(2-py1'idyl)-formimino-octylether 1. 7-0. 8 3. 5 0. 31-0. 16 N- (2-pyridyl) -iorrnimino-dodecylether. 3. 5-7. 5 7. 5 3. 5 Previously described 01-4 alkyl ethers:

N (Z-pyridyl) -formimino-methylether 7. 5-15. 5 31-62 15. 5 N-(S-pyltidyl)formimino-propylether 7. 5 15. 5 15. 5 N -(4-pyridyl) -forrnimino-ethy1ether 15. 5-31 15. 5 31-62 N-(5-chloro-2-pyridyl) -iormiminoethyl-ether 7. 5-15. 5 15.5 15. 5 N-(3-chloro-2-pyridyl) formiminohyl-ether 15. 5-31 31 15. 5

Table II shows similar minimal inhibiting concentrations in mg. percent, compared with those of three wellknown anthelmintic agents.

TABLE II Minimal inhibiting concentrations in mg. percent against- Enchytraeus Tubzfex Compound albidus rivulorum N- (4-pyn'dyl) -formimino-heptylether 3. 5-7. 5 15. 5-31 N-(4-pyridyl)-iormimino-decylether 1. 7-3. 5 15. 5 N-(4-pyridyl) -formimino-eetylether. 15. 5 15. 5-31 N-(4-pyn'dyl)-formimino-benzylether 7. 5 7. 5 N-(4-pyridyl) -fo1'mimino-phenylethyl-ethe 3. 6-7. 5 7. 5 N-(3-pyridyl)-formimino-cetyletl1er 15. 5-31 3. 5-7. 5 N-(3-pyridy1) -formimino-decylether 1. 7-0. 8 1. 7-0. 8 N-(3-pyridy1)-forminimocyc1ohexyl-ether- 15. 5 1. 7-0. 8 N-(2-pyn'dyl) -formimino-heptylether 7 5-15. 5 1. 7-0. 8 N-(Z-pyridyl)-forrnimino-phenylethyl-ether- 1. 7-0. 8 15. 5-7. 5 N-(2-pyridyl)-formimino-cyelopentyl-ether 15. 5-31 15. 5 N-(Z-pyridyl)-formimino-benzylether 1. 7-0. 8 0. 4-0. 8 N-(4-methyl-2-pyridyD-formimino-(fi-diethylam oethyl) th 15. 5-31 5-7. 5 N-(5-chloro-2pyridyl)-formimino-4=-heptylether 15. 5-7. 5 7. 5 Known compounds for comparison:

2'5-dichloro-4-nitrosalicylanilide (Niclosamide) 15. 5-7. 5 15. 5-31 2- (fl-methoxyethyD-pyridine (Methyridine) 7. 5-3. 5 15. 5-31 1-l(2-diethylaminoethy1) -amino]4-methylthioxanthen e hydro-chloride 15 31 1 (Lueanthone Hydrochloride) metallic sodium with g. of ,B-diethylamino ethanol as described in Example 2. The obtained N-(4-methyl-2- EXAMPLE 9 The mixture of 18.46 g. (0.1 mol.) of N-(5-chloro-2- pyridyl)-formimino ethyl ether, 11.62 g. (0.1 mol.) of heptan-4-ol and 0.1 g. of metallic sodium was reacted as described in Example 2. The obtained N-(5-chloro-2- pyridyl)-formimino 4'-heptyl ether boils under 0.05 mm. Hg at 162182 C. The following additional compounds have also been prepared by the method of the above example:

N- 3-pyridy1) -formimino-,B-phenylethyletherB.P. =138139 C.

N- (S-nitro-Z-pyridyl -formimino-b enzyletherB.P. =145-146 C.

The new compounds show significant pharmacological advantages over those of the lower alkyl analogues of Hungarian Pat. No. 153,520 issued Mar. 22, 1967. Table I shows the minimal inhibiting concentrations in mg. percent against Enchytraeus albidus (E), Tubifex rivu- Having described our invention, we claim: 1. An N-pyridyl-formimino ether of the formula wherein R is a member selected from the group consisting of straight or branched chain alkyl having 7-16 carbon atoms, cycloalkyl having 5-6 carbon atoms, benzyl, phenylethyl, dimethylaminoethyl and diethylaminoethyl,

and R is a member selected from the group consisting of hydrogen, halogen, nitro and lower alkyl. 

